<?php

namespace App\Http\Controllers\Api;

use App\Models\Calendar;
use App\Models\Configuration;
use Symfony\Component\HttpFoundation\Response;

class SchoolCalendarController extends BaseApiController
{
    protected Calendar $calendar;
    protected Configuration $config;
    protected string $schoolYear;
    protected string $semester;

    public function __construct()
    {
        parent::__construct();
        $this->calendar = model(Calendar::class);
        $this->config   = model(Configuration::class);
        $this->schoolYear    = (string) ($this->config->getConfig('school_year') ?? '');
        $this->semester      = (string) ($this->config->getConfig('semester') ?? '');
    }

    /**
     * GET /api/v1/school-calendar
     * Get calendar events filtered by school_year and optional semester
     */
    public function index()
    {
        $schoolYear = (string) ($this->request->getGet('school_year') ?? $this->schoolYear);
        $semester   = $this->request->getGet('semester');

        try {
            $query = $this->calendar->newQuery();

            if ($schoolYear !== '') {
                $query->where('school_year', $schoolYear);
            }

            if ($semester !== null && $semester !== '') {
                $events = $query->where('semester', $semester)->orderBy('date', 'ASC')->get()->toArray();
            } else {
                $events = $query->orderBy('date', 'ASC')->get()->toArray();
            }

            return $this->success([
                'events'      => $events,
                'school_year' => $schoolYear,
                'semester'    => $semester,
            ], 'Calendar events retrieved successfully');
        } catch (\Throwable $e) {
            log_message('error', 'School calendar error: ' . $e->getMessage());
            return $this->respondError('Failed to retrieve calendar events', Response::HTTP_INTERNAL_SERVER_ERROR);
        }
    }

    /**
     * GET /api/v1/school-calendar/{id}
     * Get a single calendar event
     */
    public function show($id = null)
    {
        $event = $this->calendar->find($id);
        if (!$event) {
            return $this->error('Event not found', Response::HTTP_NOT_FOUND);
        }

        return $this->success($event, 'Event retrieved successfully');
    }

    /**
     * POST /api/v1/school-calendar
     * Create a new calendar event
     */
    public function store()
    {
        $payload = $this->payloadData();
        if (empty($payload)) {
            return $this->error('Invalid request data', Response::HTTP_BAD_REQUEST);
        }

        $rules = [
            'title' => 'required|min_length[3]',
            'start' => 'required|valid_date[Y-m-d]',
        ];

        $errors = $this->validateRequest($payload, $rules);
        if (!empty($errors)) {
            return $this->respondValidationError($errors);
        }

        $data = [
            'title'          => trim((string) ($payload['title'] ?? '')),
            'description'    => trim((string) ($payload['description'] ?? '')),
            'date'           => trim((string) ($payload['start'] ?? '')),
            'notify_parent'  => isset($payload['notify_parent']) && $payload['notify_parent'] ? 1 : 0,
            'notify_teacher' => isset($payload['notify_teacher']) && $payload['notify_teacher'] ? 1 : 0,
            'notify_admin'   => isset($payload['notify_admin']) && $payload['notify_admin'] ? 1 : 0,
            'no_school'      => isset($payload['no_school']) && $payload['no_school'] ? 1 : 0,
            'school_year'    => trim((string) ($payload['school_year'] ?? $this->schoolYear)),
            'semester'       => trim((string) ($payload['semester'] ?? $this->semester)),
        ];

        try {
            $event = $this->calendar->create($data);
            log_message('info', 'Event saved successfully: ' . print_r($data, true));
            return $this->success($event, 'Event added successfully', Response::HTTP_CREATED);
        } catch (\Throwable $e) {
            log_message('error', 'Failed to save event: ' . $e->getMessage());
            return $this->respondError('Failed to save the event', Response::HTTP_INTERNAL_SERVER_ERROR);
        }
    }

    /**
     * PATCH /api/v1/school-calendar/{id}
     * Update a calendar event
     */
    public function update($id = null)
    {
        $event = $this->calendar->find($id);
        if (!$event) {
            return $this->error('Event not found', Response::HTTP_NOT_FOUND);
        }

        $payload = $this->payloadData();
        if (empty($payload)) {
            return $this->error('Invalid request data', Response::HTTP_BAD_REQUEST);
        }

        $rules = [
            'title' => 'permit_empty|min_length[3]',
            'start' => 'permit_empty|valid_date[Y-m-d]',
        ];

        $errors = $this->validateRequest($payload, $rules);
        if (!empty($errors)) {
            return $this->respondValidationError($errors);
        }

        $data = [];

        if (isset($payload['title'])) {
            $data['title'] = trim((string) $payload['title']);
        }
        if (isset($payload['description'])) {
            $data['description'] = trim((string) $payload['description']);
        }
        if (isset($payload['start'])) {
            $data['date'] = trim((string) $payload['start']);
        }
        if (isset($payload['notify_parent'])) {
            $data['notify_parent'] = $payload['notify_parent'] ? 1 : 0;
        }
        if (isset($payload['notify_teacher'])) {
            $data['notify_teacher'] = $payload['notify_teacher'] ? 1 : 0;
        }
        if (isset($payload['notify_admin'])) {
            $data['notify_admin'] = $payload['notify_admin'] ? 1 : 0;
        }
        if (isset($payload['no_school'])) {
            $data['no_school'] = $payload['no_school'] ? 1 : 0;
        }
        if (isset($payload['school_year'])) {
            $data['school_year'] = trim((string) $payload['school_year']);
        }
        if (isset($payload['semester'])) {
            $data['semester'] = trim((string) $payload['semester']);
        }

        try {
            $this->calendar->update($id, $data);
            $updatedEvent = $this->calendar->find($id);
            return $this->success($updatedEvent, 'Event updated successfully');
        } catch (\Throwable $e) {
            log_message('error', 'Failed to update event: ' . $e->getMessage());
            return $this->respondError('Failed to update the event', Response::HTTP_INTERNAL_SERVER_ERROR);
        }
    }

    /**
     * DELETE /api/v1/school-calendar/{id}
     * Delete a calendar event
     */
    public function delete($id = null)
    {
        $event = $this->calendar->find($id);
        if (!$event) {
            return $this->error('Event not found', Response::HTTP_NOT_FOUND);
        }

        try {
            $this->calendar->delete($id);
            return $this->success(null, 'Event deleted successfully');
        } catch (\Throwable $e) {
            log_message('error', 'Failed to delete event: ' . $e->getMessage());
            return $this->respondError('Failed to delete the event', Response::HTTP_INTERNAL_SERVER_ERROR);
        }
    }

    /**
     * GET /api/v1/school-calendar/view/parent
     * Get calendar events formatted for parent view
     */
    public function calendarParentView()
    {
        $formattedEvents = $this->calendarView('parent');
        return $this->success(['events' => $formattedEvents], 'Parent calendar view retrieved successfully');
    }

    /**
     * GET /api/v1/school-calendar/view/teacher
     * Get calendar events formatted for teacher view
     */
    public function calendarTeacherView()
    {
        $formattedEvents = $this->calendarView('teacher');
        return $this->success(['events' => $formattedEvents], 'Teacher calendar view retrieved successfully');
    }

    /**
     * GET /api/v1/school-calendar/view/admin
     * Get calendar events formatted for admin view
     */
    public function calendarAdminView()
    {
        $formattedEvents = $this->calendarView('admin');
        return $this->success(['events' => $formattedEvents], 'Admin calendar view retrieved successfully');
    }

    /**
     * Private method to format calendar events based on audience visibility rules
     */
    private function calendarView(?string $audience = null): array
    {
        // Filter events by school year
        $query = $this->calendar->newQuery();
        if ($this->schoolYear !== '') {
            $query->where('school_year', $this->schoolYear);
        }
        $events = $query->orderBy('date', 'ASC')->get()->toArray();

        // Apply audience visibility rules:
        // - If no checkboxes selected (all notify_* = 0) => visible to everyone
        // - Otherwise visible only to the selected audience
        if (in_array($audience, ['parent', 'teacher', 'admin'], true)) {
            $events = array_values(array_filter($events, function ($event) use ($audience) {
                $p = (int) ($event['notify_parent'] ?? 0);
                $t = (int) ($event['notify_teacher'] ?? 0);
                $a = (int) ($event['notify_admin'] ?? 0);
                $ns = (int) ($event['no_school'] ?? 0);

                $hasAny = ($p + $t + $a) > 0;

                // If marked as no_school, it should be visible to all audiences
                if ($ns === 1) {
                    return true;
                }

                if (!$hasAny) {
                    // No audience explicitly selected: show to everyone
                    return true;
                }

                // Audience explicitly selected: restrict to matching audience
                if ($audience === 'parent') {
                    return $p === 1;
                }
                if ($audience === 'teacher') {
                    return $t === 1;
                }
                if ($audience === 'admin') {
                    return $a === 1;
                }

                return true;
            }));
        }

        // Format for FullCalendar
        $aud = $audience; // capture for closure
        $formattedEvents = array_map(function ($event) use ($aud) {
            $p  = (int) ($event['notify_parent'] ?? 0);
            $t  = (int) ($event['notify_teacher'] ?? 0);
            $a  = (int) ($event['notify_admin'] ?? 0);
            $ns = (int) ($event['no_school'] ?? 0);

            $backgroundColor = null;

            // Color no-school events yellow on teacher and parent calendars
            if (in_array($aud, ['teacher', 'parent'], true) && $ns === 1) {
                $backgroundColor = '#ffc107'; // yellow
            }

            // Highlight events dedicated to staff (teachers/admins) only in green
            // Definition: visible to staff but not to parents, and not a no-school marker
            if (in_array($aud, ['teacher', 'admin'], true) && $backgroundColor === null) {
                $isStaffOnly = ($p === 0 && ($t === 1 || $a === 1) && $ns === 0);
                if ($isStaffOnly) {
                    // Use a distinct green to differentiate from the default blue
                    $backgroundColor = '#28a745';
                }
            }

            // Title-casing for "no school" phrase when marked as no_school
            $title = $event['title'] ?? 'Untitled';
            if ($ns === 1 && is_string($title)) {
                // Replace common variants with Title Case
                $title = preg_replace('/\bno\s*[- ]\s*school\b/i', 'No School', $title);
            }

            return [
                'id'          => $event['id'],
                'title'       => $title,
                'start'       => $event['date'] ?? '', // FullCalendar expects 'start'
                'description' => $event['description'] ?? '',
                'extendedProps' => [
                    'semester'        => $event['semester'] ?? '',
                    'school_year'     => $event['school_year'] ?? '',
                    'notify_parent'   => $p,
                    'notify_teacher'  => $t,
                    'notify_admin'    => $a,
                    'no_school'       => $ns,
                    'backgroundColor' => $backgroundColor,
                ]
            ];
        }, $events);

        return $formattedEvents;
    }
}